Reaper

I’ve been using Reaper on Windows for years, but I need a new computer and I’m thinking of getting a Mac. Will Reaper on Mac be able to open my files, or do I need to tweak anything?

In Reaper, I matched the fader levels and flipped the polarity of the new track. I should hear nothing when both tracks play, right? But I don’t. Why not?

I'm having real difficulty routing a source track to FabFilter's side-chain when using Reaper. Has anyone done this before?

My band tracked some songs at a local studio using their Pro Tools rig and I want to mix the tracks at home in Reaper.